Valve delivery system

ABSTRACT

A valve delivery system including a valve prosthesis, a first catheter, and a second catheter. The valve prosthesis comprises a first frame and a second frame. The first frame is configured to attach to the second frame. The first frame is releasably disposable at the distal end of the first catheter. The second catheter is slidably disposable over the first catheter. The second frame is releasably disposable at a distal end of the second catheter.

BACKGROUND

This application is a divisional of U.S. application Ser. No.15/345,113, filed Nov. 7, 2016, entitled “Valve Delivery System,” theentire teachings of which are incorporated herein by reference in theirentirety.

The heart is a four-chambered pump that moves blood efficiently throughthe vascular system. Blood enters the heart through the vena cava andflows into the right atrium. From the right atrium, blood flows throughthe tricuspid valve and into the right ventricle, which then contractsand forces blood through the pulmonic valve and into the lungs.Oxygenated blood returns from the lungs and enters the heart through theleft atrium and passes through the mitral valve into the left ventricle.The left ventricle contracts and pumps blood through the aortic valveinto the aorta and to the vascular system.

Diseased or otherwise deficient heart valves can be repaired or replacedwith an implanted prosthetic heart valve. Conventionally, heart valvereplacement surgery is an open-heart procedure conducted under generalanesthesia, during which the heart is stopped and blood flow iscontrolled by a heart-lung bypass machine. Traditional open surgeryinflicts significant patient trauma and discomfort, and exposes thepatient to a number of potential risks, such as infection, stroke, renalfailure, and adverse effects associated with the use of the heart-lungbypass machine, for example.

Due to the drawbacks of open-heart surgical procedures, there has beenan increased interest in minimally invasive and percutaneous replacementof cardiac valves. With these percutaneous transcatheter (ortransluminal) techniques, a valve prosthesis is compacted for deliveryin a catheter and then advanced, for example, through an opening in thefemoral artery and through the descending aorta to the heart, where theprosthesis is then deployed in the annulus of the valve to be repaired(e.g., the aortic valve annulus).

Various types and configurations of prosthetic heart valves areavailable for percutaneous valve procedures, and continue to be refined.The actual shape and configuration of any particular prosthetic heartvalve is dependent to some extent upon the native shape and size of thevalve being repaired (i.e., mitral valve, tricuspid valve, aortic valve,or pulmonary valve). In general, prosthetic heart valve designs attemptto replicate the functions of the valve being replaced and thus willinclude valve leaflet-like structures. With a bioprosthesesconstruction, the replacement valve may include a valved vein segmentthat is mounted in some manner within an expandable stent frame to makea valved stent (or “stented prosthetic heart valve”). For manypercutaneous delivery and implantation systems, the stent frame of thevalved stent is made of a self-expanding material and construction. Withthese systems, the valved stent is crimped down to a desired size andheld in that compressed arrangement within an outer sheath, for example.Retracting the sheath from the valved stent allows the stent toself-expand to a larger diameter, such as when the valved stent is in adesired position within a patient. In other percutaneous implantationsystems, the valved stent can be initially provided in an expanded oruncrimped condition, then crimped or compressed on a balloon portion ofcatheter until it is as close to the diameter of the catheter aspossible. Once delivered to the implantation site, the balloon isinflated to deploy the prosthesis. With either of these types ofpercutaneous stent delivery systems, conventional sewing of theprosthetic heart valve to the patient's native tissue is typically notnecessary.

The prosthetic valve can be large, presenting challenges in deliveryinto the anatomy for implantation. Delivery through the septum canpresent additional challenges. Two part prosthetic valves, wherein afirst part of the valve is fastened to the second part of the valve canbe less bulky to deliver, but delivery can be time consuming. Typicallythe first part is loaded and delivered on a catheter, then the cathetermust be withdrawn, and then the second part is delivered and fastened tothe first part.

In light of the above, a need exists for a more efficient manner ofdelivering and deploying a two part prosthetic valve.

SUMMARY

One aspect of the present invention relates to a valve delivery systemincluding a valve prosthesis, a first catheter, and a second catheter.The valve prosthesis comprises a first frame and a second frame. Thefirst frame is configured to attach to the second frame. The first frameis releasably disposable at the distal end of the first catheter. Thesecond catheter is slidably disposable over the first catheter. Thesecond frame is releasably disposable at a distal end of the secondcatheter.

Another aspect of the present invention relates to a method ofimplanting a valve prosthesis. The method includes advancing a firstframe disposed at a distal end of a first catheter distal into apatient's vasculature, positioning the first frame distal to a nativevalve, advancing a second frame disposed at a distal end of a secondcatheter into a patient's vasculature, the second catheter disposedaround the first catheter, positioning the second frame at a nativevalve annulus of the native valve, expanding the second frame at thevalve annulus, repositioning the first frame at the valve annulus,expanding the first frame, and securing a first frame to the secondframe. At least a portion of the first frame is within at least aportion of the second frame when the first frame is expanded.

Another aspect of the present invention relates to a method ofimplanting a valve prosthesis. The method includes advancing a firstframe disposed at a distal end of a first catheter distal into apatient's vasculature and advancing a second frame disposed at a distalend of a second catheter into a patient's vasculature. The secondcatheter and second frame is disposed around the first catheter. Themethod also includes positioning the first frame at a native valve,deploying the first frame, repositioning the second frame at the nativevalve, deploying the second frame, receiving the second frame within thefirst frame, and securing the second frame to the first frame.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A-1B are schematic cross-sectional illustrations of an exampletwo-part prosthetic heart valve deliverable in accordance with aspectsof the present disclosure;

FIG. 2A is a schematic side view illustration of an example deliverysystem in accordance with aspects of the present disclosure;

FIG. 2B is a schematic cross-sectional view illustration of an exampledelivery system in accordance with aspects of the present disclosure;

FIGS. 3A-3D are schematic illustrations of a method of delivering atwo-part prosthetic heart valve in accordance with aspects of thepresent disclosure.

DETAILED DESCRIPTION

A prosthetic heart valve as used in accordance with the various systems,devices, and methods of the present disclosure may include a widevariety of different configurations, such as a bioprosthetic heart valvehaving tissue leaflets or a synthetic heart valve having a polymeric,metallic, or tissue-engineered leaflets, and can be specificallyconfigured for replacing any heart valve. Thus, the prosthetic heartvalve useful with the systems, devices, and methods of the presentdisclosure can be generally used for replacement of a native aortic,mitral, pulmonic, or tricuspid valves, for use as a venous valve, or toreplace a failed bioprosthesis, such as in the area of an aortic valveor mitral valve, for example.

FIGS. 1A-1B are schematic cross-sectional illustrations of an exampletwo-part prosthetic heart valve 10 deliverable in accordance withaspects of the present disclosure. In general terms, the prostheticheart valve 10 deliverable in accordance with the delivery system 20(see, e.g., FIGS. 2A-2B) of the present disclosure include a first frame12 and a second frame 14 coupleable to the first frame 12, with thefirst and second frames 12, 14 having normal, expanded arrangements andcollapsible to compressed arrangements for independent loading onto thedelivery system. FIG. 1A illustrates the first frame 12 and the secondframe 14 of an example prosthetic heart valve 10 in an unassembledexpanded arrangement and FIG. 1B illustrates the first frame 12 andsecond frame 14 in an assembled expanded arrangement. The first andsecond frames 12, 14 can be coupled together after delivery andexpandable deployment at the desired position within the patient, asdiscussed further below.

The prosthetic valve 10 can be any valve suitable to be delivered anddeployed within the patient as two separate portions, or frames 12, 14,and is sized and shaped as appropriate for the type of heart valvereplacement needed. The frames 12, 14 are support structures that cancomprise a number of struts or wire portions arranged relative to eachother to provide a desired compressibility and strength to theprosthetic heart valve 10. In one example embodiment, the second frame14 can be a valvular structure frame and the first frame 12 can be areinforced frame. In one embodiment, the frames 12, 14 are generallytubular support structures, with the second frame 14 including valvestructure leaflets. The leaflets can be formed from a variety ofmaterials, such as autologous tissue, xenograph material, or syntheticsas are known in the art. In one embodiment, the frames can be formedusing high-strength nano-manufactured NiTi films produced at AdvanceBioProsthetic Surfaces (ABPS), for example. The second frame 14generally includes at least two (or three) leaflets; however,replacement prosthetic heart valves of the types described herein canincorporate more or less than three leaflets.

The second frame 14 that is fastened to the first frame 12 can be lessbulky than the first frame 12. In one example illustrated in FIGS.1A-1B, the first frame 12 can have a substantially truncatedhyperboloidal shape in an expanded position, with a larger base andsmaller neck. The first frame 12 can have a curvature that is concavetowards the aortic wall. The second frame 14 can be a substantiallycylindrical structure. The first frame 12 is expandable and capable ofmaintaining the body channel open in its expanded state and supportingthe collapsible second frame 14. In one embodiment, the first and secondframes 12, 14 each have mateable couplers 16, 18 that securely fastenthe first and second frames 12, 14 together. Any suitable coupling meansare acceptable. A perimeter of the second frame 14 is coupled to aninterior portion of the first frame 12. The first frame 12 is fastenedalong a substantial portion of the second frame 14. In one embodiment,the frames 12, 14 are self-expanding and are formed of a shaped memoryalloy, for example. In another embodiment, the first and second frames12, 14 are balloon expandable.

FIGS. 2A and 2B are schematic side and cross-sectional viewillustrations of an example valve delivery system 20 in accordance withaspects of the present disclosure. The valve delivery system 20 includesa first catheter 22 and a second catheter 24 coaxially disposed over thefirst catheter 22. The first and second catheters 22, 24 are slidablydisposed relative to one another along a longitudinal axis 26. The twopart valve delivery provides that each frame 12, 14 of the two partprosthetic heart valve 10 has a smaller external diameter when incollapsed states, since each frame 12, 14 to be expanded, consideredseparately, is smaller than in combination. The valve delivery system 20distally stores and delivers the two portions, or frames 12, 14, of theprosthetic heart valve 10. For example, during delivery a distal end 28of the first catheter 22 can be proximal to, but spaced from, a distalend 29 of the second catheter 24.

The first frame 12 can be collapsed and loaded onto a first, inner,catheter 22 and the second frame 14 can be collapsed and loaded onto thesecond catheter 24 in preparation of delivery. The second catheter 24and the second frame 14 are circumferentially and coaxially disposedaround the first catheter 22. With additional reference to FIGS. 3A-3D,a guide wire can be disposed within a lumen 30 of the first catheter 22to help position the first and second frames 12, 14 of the implantablevalve 10 within the native valve opening. Additionally, in someembodiments, at least the first catheter 22 can include an inner tube 32and an outer tube 34 with the inner tube 32 to prevent the stent-graftfrom moving back as a capsule sheath 36 is withdrawn. In one embodiment,capsules 36, 38 are disposed at the distal ends 28, 29 of the first andsecond catheters 22, 24, respectively, to releasably contain the firstand second frames 12, 14 for delivery. In another embodiment, instead ofcapsule sheaths, at least one of the distal ends 28, 29 of the first andsecond catheters 22, 24 include inflatable balloons that the first andsecond frames 12, 14 are disposed.

FIGS. 3A-3D are schematic illustrations of a method of delivering atwo-part prosthetic heart valve 100 with a valve delivery system 200 ofthe present disclosure. Intraluminal deployment is effected using thevalve delivery system 200, similar to that of valve delivery system 20described above. As described below, a first frame 112 and a secondframe 114 are independently and coaxially collapsed for delivery andindependently and coaxially expanded when deployed. A first catheter 222and a second catheter 224 are arranged for relative axial movement withthe first and second frames 112, 114 compressed and disposed onto thedistal ends of the first and second catheters 222, 224, respectfully.

In one embodiment, as illustrated in FIG. 3A, the first catheter 222 ismaneuvered, typically routed through a vessel 302 (e.g., lumen) of apatient 300, until a distal end 228 of the first catheter 222 upon whichthe first frame 112 is releasably disposed, is positioned in thevicinity of the intended treatment site, such as a native valve 304 of aheart 306. The first, inner, catheter 222 is tracked in over a guidewire 225 in a direction indicated by arrow A₁ to position a distal end228 (including, e.g., a first capsule or a first balloon) of the firstcatheter 222 for disposing the first frame 112 in a position thatextends the first catheter 222 through and past the native valve 304. Asillustrated, the delivery path can occur through the patient's septum308 and continue by turning approximately 90° downward through thenative mitral valve 304.

As illustrated in FIG. 3B, the second catheter 224 is then tracked overthe guide wire 225 and over the first catheter 222 in the directionindicated by arrow A₁ to position a distal end 229 (including, e.g., asecond capsule or a second balloon) upon which the second frame 114 isreleasably disposed, within the native valve 304 opening and into thedesired deployment position. The first catheter 222 can assist withcentering of the second catheter 224 and second frame 114 both coaxiallydisposed around the first catheter 222 within the native valve 304opening. As the first catheter 222 carrying the first frame 112 at thedistal end 228 remains extended through the native valve 304, the nativevalve 304 function is inhibited. The second catheter 224 carrying thesecond frame 114 at the distal end 229 can be quickly moved intoposition with coaxially routed over the first catheter 222 to deploy thefirst and second frames 112, 114 and begin valve function can beginagain, as described further below.

The first and second catheter 222, 224 of the valve delivery system 200are successively, coaxially disposed with respect to the native valve304. During insertion and routing along the delivery pathway, the distalend 229 of the second catheter 224 is spaced from the distal end 228 ofthe first catheter 222 such that a portion of the first catheter 222 isexposed between the two distal ends 228, 229. In one embodiment, theportion of the first catheter 222 between the distal ends 228, 229 isrelatively small such that the first distal end 228 can be quicklydelivered and repositioned to deploy the first frame 112 after thesecond frame 114 is deployed. The portion of the first catheter 222extending between the first and second distal ends 228, 229 can performa hinge-like function to facilitate navigation of bends in the deliverypath. In this manner, the catheters 222, 224 can bend and the first andsecond frames 112, 114 releasably contained or disposed therein cantraverse a more torturous delivery path than otherwise possible with asingle, larger delivery payload of a complete prosthetic valve or if thetwo parts, or frames 112, 114, were disposed together longitudinally ina series.

With reference to FIG. 3C, the first catheter 222 is maintained distalto the native valve 304 while the second catheter 224 is withdrawn alongthe first catheter 222 in a direction indicated by arrow A₂. As thesecond catheter 224 is withdrawn, the second frame 114 is graduallyexposed. The exposed portion of the second frame 114 radially expands sothat at least a portion of the expanded portion is in substantiallyconforming surface contact with a portion of the interior of the nativeheart valve 304 opening. The second frame 114 is fully deployed andreleased from the distal end 229 and the second catheter 224 iswithdrawn.

With reference to FIG. 3D, the first catheter 222 is withdrawn along theguide wire 225 in the direction indicated by arrow A₂ to reposition thefirst distal end 228 containing the first frame 112 at least partiallywithin the second frame 114 and the native valve 304 opening. The firstframe 112 is deployed and the first frame 112 expands within the secondframe 114. The first and second frames 112, 114 are secured together.The attachment of the first and second frames 112, 114 can be viamatable couplers as described above with respect to FIGS. 1A-1B, forexample, or via any other suitable secure attachment. After the firstframe 112 is fully deployed, the first catheter 222 can then continue tobe withdrawn along the delivery path in the direction indicated by arrowA₂.

The first and second catheters 222, 224 may be inserted, routed anddeployed in any order and are not limited to the order described above.Further, in one embodiment, both the first and second frames 112, 114are self-expanding. In another embodiment, both the first and secondframes 112, 114 are balloon expandable. In another embodiment, one ofthe first and second frames 112, 114 is self-expanding and the other ofthe first or second frame 112, 114 is balloon expandable.

Although the present disclosure has been described with reference topreferred embodiments, workers skilled in the art will recognize thatchanges can be made in form and detail without departing from the spiritand scope of the present disclosure.

What is claimed is:
 1. A valve delivery system, comprising: a valveprosthesis including a first frame and a second frame, the first frameconfigured to attach to the second frame; a first catheter including adistal end, the first frame releasably disposable at the distal end; anda second catheter slidably disposable over the first catheter, thesecond frame releasably disposable at a distal end of the secondcatheter.
 2. The valve delivery system of claim 1, wherein the secondframe is arranged circumferentially around the first catheter.
 3. Thevalve delivery system of claim 1, wherein the first and second framesare releasably constrained within capsules.
 4. The valve delivery systemof claim 1, wherein at least one of the first frame and the second frameincludes a self-expanding frame.
 5. The valve delivery system of claim1, wherein the second frame is configured to attach at an interiorportion of the first frame.
 6. The valve delivery system of claim 1,wherein first and second frames are spaced apart from one another alonga longitudinal axis defined by the first catheter.